GENETIC ANALYSIS OF MEIOTIC CENTROMERE FUNCTION

描述：这项提议的具体目的是从基因上识别 并表征着丝粒的组装和功能所需的基因 在减数分裂中。这些研究将在雄性果蝇身上进行 一种模式遗传有机体，其着丝粒出现在功能上 在结构上与人类着丝粒相似。突变株已被诱导 使用转座子诱变，并筛选它们对 减数分裂不稳定双着丝粒染色体(染色体)的传递 具有两个着丝粒)。突变要么增加，要么优先 选择了减数分裂传递减少的染色体。这些遗嘱 从遗传学和细胞学的角度确定候选基因 着丝粒结构和/或调控蛋白。此外，a 总共缺失80%的缺乏症染色体的集合 常染色体常染色质的一部分将在反式中测试对 这种双着丝粒染色体的分离。此缺陷筛查将 确定基因组中包含对基因至关重要的基因的区域 双着丝粒的稳定性。选定的突变体将通过遗传和 分子方法，并通过基于转座子的方法或通过 染色体行走。克隆的cDNA将在细菌或 杆状病毒产生抗原以产生多克隆抗体。 此外，还将进一步研究双着丝粒染色体的性质 从基因上来说。双着丝粒的两个着丝粒将分离并 在不同的染色体上恢复，以便测试每个染色体的属性 着丝粒个体。新的双着丝粒染色体将产生为 原双着丝粒的衍生品。这些将被描述为 从遗传学和细胞学的角度来确定影响 双着丝粒染色体着丝粒的有丝分裂和减数分裂行为。

DESCRIPTION: The specific aims of this proposal are to genetically identify and characterize genes required for the assembly and function of centromeres in meiosis. These studies will be carried out in male Drosophila melanogaster, a model genetic organism whose centromeres appear functionally and structurally similar to human centromeres. Mutants have been induced using transposon mutagenesis, and were screened for their effects on the transmission of a meiotically unstable dicentric chromosome (a chromosome with two centromeres). Mutations that either increased or preferentially decreased meiotic transmission of this chromosome were selected. These will be characterized genetically and cytologically to identify candidate genes for centromere structural and/or regulatory proteins. In addition, a collection of deficiency-bearing chromosomes that together delete 80 percent of the autosomal euchromatin will be tested in trans for effects on the segregation of this dicentric chromosome. This deficiency screen will identify regions of the genome that contain genes important for the stability of the dicentric. Selected mutants will mapped by genetic and molecular methods, and cloned either by transposon-based methods or by chromosomal waLking. Cloned cDNAs will be expressed in bacteria or baculovirus to produce antigen for the production of polyclonal antibodies. Additionally, the nature of the dicentric chromosome will be further studied genetically. The two centromeres of the dicentric will be detached and recovered on separate chromosomes to allow tests of the properties of each centromere individually. New dicentric chromosomes will be generated as derivatives of the original dicentric. These will be characterized genetically and cytologically to identify properties that influence the mitotic and meiotic behavior of centromeres of dicentric chromosomes.